1. Field of the Invention
This invention relates to a dye composition for keratinous fibers, and, more particularly, to a dye composition for keratinous fibers which is capable of dyeing keratinous fibers such a hairs and the like at a high degree of saturation and vividness, and to a p-phenylenediamine derivative useful as a developer when formulated into such a dye composition. The invention also is directed to a process for preparing the p-phenylenediamine derivatives.
2. Description of the Background
Oxidizing dyes, in which a developer and a coupling agent are employed in combination, have widely been used for dyeing keratinous fibers such as hairs or the like. These oxidizing dyes make use of the strong dyeing capability of oxidizing coloring substances which are produced by the oxidizing-coupling reaction of a developer and a coupling agent. Para-phenylenediamine derivatives, diaminopyridine derivatives, 4-aminopyrazolone derivatives, hetero-cyclic hydrazone, and the like are used as the developer.
These conventional oxidizing dyes have defects in their performance which are yet to be satisfied in terms of saturation or vividness of colors, dyeing capability, and fastness. Development of a dye which is free from these defects has, therefore, been desired.
Performance of an oxidizing dye such as saturation or vividness of colors, dyeing capability, fastness, and the like is greatly dependent upon the characteristics of the developer used. It is, therefore, very important in eliminating the above defects of oxidizing dyes to find a developer possessing an excellent characteristics.
The present inventors have undertaken extensive studies in order to overcome the above problems in oxidizing dyes, and as a result found that use of a trifluoromethylated aniline derivative for dyeing keratinous fibers provides a high degree of saturation and vividness of colors as well as good fastness. This finding has led to the completion of this invention.